This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The long-term objective is to engineer macromolecular components for nanoscale structures that can be assembled by design. The molecular complex under investigation here represents a way to link streptavidin-containing struts to node molecules of various symmetries. We propose to use cryo-EM to provide a structural assay of the engineered nano-structures.